1. Field of the Invention
The present invention relates to a road environment recognition device and a method of recognizing a road environment.
2. Description of Related Art
JP-A-2005-10891 discloses a road shape recognition device mounted to a vehicle. The vehicle is driven on a road, and the recognition device recognizes a shape of the road as a road environment. The recognition device includes a detecting sensor (e.g., laser-radar) detecting a forward object in front of the vehicle. The forward object is a candidate for a roadside structure forming the shape of the road. Further, position information of the forward object can be provided after the detecting sensor finishes the detection of the forward object. That is, the position information of the forward object can be provided both in the detection time and after the detection time. The shape of the road can be recognized based on the position information both in the detection time and after the detection time. The shape of the road can be accurately recognized, even if the number of the candidates in the detection time is small, because the position information after the detection time can be used.
The position information after the detection time can be provided by calculations. When the detecting sensor finishes the detection of the forward object, the position of the forward object is defined as an initial position. The position of the forward object after a sampling period is calculated by using movement information of the vehicle during the sampling period.
However, the recognition device detects only the forward object to be the candidate for the roadside structure. Therefore, the road environment cannot comprehensively be recognized.